What is the purpose of linking service offering and catalog items?

[Suggy]

What is the benefit that I will get when I link the service of friends with catalogue items? 

Also I heard that we need to tag one service offering to one catalogue item only

or

one service offering to multiple catalogue items. 

Not sure which is the recommended one. Please let me know if you are aware of this

[Mathew Hillyard]

Another really good reason to link a catalog item to a service offering is to identify the subscribers to the service offering - there are related lists that can show this data. In the event of issues with that service offering you can send targeted communications to subscribers instead of blanket notifications to (potentially) the whole organisation.

I hope this helps!

Mat